The figure below represents this concept.Ī needle valve is what you would want if you needed to adjust the flow. Very clear to anyone reading the schematic. A dot means that they are connected and a hump means they aren’t. With this, there is no guessing as to what my intent was. Personally, I like adding the hump and using the dot. In all honesty, the change came because it was far easier to add a dot than to erase lines and make the hump. Who knew that the Black Eyed Peas were actually singing about hydraulic schematics? Ok, so the song obviously doesn’t have anything to do with hydraulics. If there is no dot, there is no connection. Now, you will need a dot to indicate crossed lines that are joined. Well, as more and more people heeded to the advice of the Black Eyed Peas saying the, “you don’t need no drama, drama, no, no drama, drama” the standards were changed. If you didn’t want the lines connected, you would draw a hump across one line adding some drama to the schematic. In the early days, if two lines crossed, they were connected. There is a little controversy with this one. The purpose of this is to simplify real-world identification.Ģ. The purpose of this line is to show that all the components within are contained in one valve block or manifold. Finally, the yellow center line around some symbols is an enclosure line or bounding box. A drain line is the opposite, a low-pressure line with higher flow.
A pilot line is a high-pressure line with low flow (1/4 gpm). The teal and green dashed lines are called pilot lines or drain lines depending on their purpose. In this case, it is a suction line for the pump. The red line indicates pressure and the blue line indicates a low-pressure return line. The basic line is a solid line that represents a working pressure hose or tube.
In the figure below, all of the basic line types are shown. In addition, colors can be added to indicate purpose of the line. In a hydraulic schematic, each line type has a unique meaning. Pneumatics will have a few extra components that we don’t use in hydraulics such as oilers, air dryers and Venturi Vacuums, but they are similar. So, the good thing about this is that while we are using hydraulics, a lot of this is directly related to pneumatics.